Not only does MSTR capture interactions with various sized participants, but MSTR also captures interactions with various sized contexts, , interaction in various distances.
To correctly measure how remote an interaction is, we note that the distance between center points [1]} should be normalized by both the image size and the size of the human and object box participating in the interaction.
Given the interaction between hbox (\(hx_1,hy_1,hx_2,hy_2\) ) and obox (\(ox_1,oy_1,ox_2,oy_2\) ), the normalized box area as area (hbox) and area (obox), we define the distance \(d_{\text{interaction}}\)  as
\(\begin{split}&d_{\footnotesize \mbox{center}} = \scriptstyle \sqrt{\left(\frac{hx_1+hx_2}{2}-\frac{ox_1+ox_2}{2}\right)^2 + \left(\frac{hy_1+hy_2}{2}-\frac{oy_1+oy_2}{2}\right)^2}, \\&d_{\footnotesize \mbox{interaction}} = d_{\footnotesize \mbox{center}} / (\footnotesize \mbox{area(hbox)}\cdot \mbox{area(obox)}).\end{split}\) 
